Flywheel ringgear replacement

[Colin Lindsay]

A mate has thrown me a low ball over the replacement of new ringgear onto my Herald flywheel. He says that when the old gear is removed I need to mark exactly where the teeth are, and replace the new gear accordingly, as the engine usually comes to rest in the same position and any movement of the flywheel teeth from the 'at rest' will play merry Hell with the starter motor Bendix.

It's one of those little posers that I'm inclined to say is rubbish, as the teeth are so closely spaced that it will make hardly any difference, yet another part of me, having experienced a starter that used to lock into the ringgear and always had to be rocked back and forth to free, makes me want to ask - just to make sure.

So: I'd say it doesn't matter. Any other views?

[Ben Caswell]

Rhubarb thats why the teeth have a lead in just make sure its round the right way,

[Pete Lewis]

Double rubarb,

Yes the engine will rest in regular postions dependant on compressions ans valvle spring loading but who is to say the stater motor

Will stop anywhere in particlular,  

I agree with Ben , the ring gear and bendix pinion are chamfered to give a lead in

On pre engaged the solenoid indexes the piniion half a tooth as it operates to ensurs they dont butt any aways line up before

 

Its thrown into mesh

[Algy]

It is worth noting that if fitting a pre-engaged starter to a engine with has a starter ring for a bendix, the teeth are flat on the side the pinion is trying to engage from, so this is a consideration if converting to pre-engaged starter or planning to in the future.

 

 

[Colin Lindsay]

Good point! I hadn't thought of fitting a high-torque starter to the Herald; certainly the 6 cylinder needs one but I always felt a good standard one was adequate for a Herald. NOW I'll have to debate which way to fit the ring gear... 

[Anglefire]

Colin, I don't think it will really matter - simply because you wouldn't change the ring gear if you were just changing to a high torque starter - as they are really a pre-engaged one, its just the solenoid is linked off the main input supply with a small jumper, so it acts like a bentix - but if you want to pre-engage it, you take the link out and wire it for pre-engage instead.

 

[Pete Lewis]

Fitted a good few you dont need to reverse the ring gear

Pre engage are indexed 1/2 a tooth on each action and if its not engaged fully it wont fire the starter motor up

So even if the lead chamfer is on the wrong side of the ring ,  you wont cause a problem

 

 

[Andrew]

Hello

I fitted a high torque starter motor to my herald about two years ago.  No problem at all with starting and engaging the ring gear, also car starts much faster.   

[Algy]

If you do turn the ring gear around you will need to chanfer the inner edge for it to fit up against the flywheel flang or it will have a gap of around 10-15thou.

[Colin Lindsay]

I think I'll just fit it as is, and save bother later on if the hi-torq unit fails and I go back to boring but reliable OE units.

(Here I am, 2 months on from the original post, and still not fitted yet....)

[Algy]

Just fitted mine but I cheat.

I heated the ring in boiling water and cool the flywheel with liquid nitrogen (obtained from a restaurant), the ring dropped on with no need to press or hammer.

[Colin Lindsay]

5 hours ago, Algy said:

Just fitted mine but I cheat.

I heated the ring in boiling water and cool the flywheel with liquid nitrogen (obtained from a restaurant), the ring dropped on with no need to press or hammer.

 

Must be some restaurant.

"Can I get you any sauce, vinegar, or any condiments with that?"

"No, just some liquid nitrogen, thanks."

[Algy]

They are one of these places were you spend £50 for a ham sandwich. They use it for making those weird foggy disserts, you know the things all art and no real substance (like the TV master chief stuff). The owner is mad on cars though and offered me a thermos full, which was an offer I had to try. My workshop looked like something from a “Carry On” horror move though, with fog us to knee height.

[Colin Lindsay]

Some of my local cafes are so good, I could use their coffee for engine degreaser. Or possibly oil, I think the last latte was EP90.

[PeteH]

Just put it in the fridge for a couple of hours. I actually left it overnight, Makes all the difference. (`er indoors wasn't impressed, but it was her car!) And I had degreased it first!. It`s a trick I learned re-assembling Fuel injectors it tropical conditions, wrapped in a rag coated with diesel. and in a plastic bag, left them in the ships frig; overnight made the close tolerance fit not need persuasion, and less likely to "jamb" on assesmbly. (we are not talking Cars here).

 

Pete